CA Foundation · Quantitative Aptitude · Equations
Solve the simultaneous equations 2x + 3y = 19 and x − y = 2. What is the value of x + y?
The sum x + y is 8. Writing x = y + 2 and substituting into 2x + 3y = 19 gives 5y = 15, so y = 3 and x = 5. These values satisfy both equations, so their sum is 8.
- A7Correct
- B8
- C9
- D5
Explanation
From x − y = 2, x = y + 2. Substituting: 2(y + 2) + 3y = 19, so 5y = 15, y = 3 and x = 5. Hence x + y = 8? Check: 5 + 3 = 8, and 2(5) + 3(3) = 19, which holds. So the sum is 8, not 7.
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